Automatic doors comprising a shutter are commonly used to shut off openings, particularly to cut off warehouses or industrial halls. These shutters are often made up of large flexible tarpaulins the lateral edges of which comprise beads which slide in guiding rail situated on each side of the opening that is to be closed. Alternatively, they can be made of rigid panels hinged to one another side by side or the shutter can be a rigid panel. Automatic doors are particularly useful when they are used to separate two rooms having different environmental conditions, such as temperature, relative humidity and the like. In such conditions, the time such door remains open must be minimized to preserve the desired conditions on both sides of the door. Doors able to open and close at high speed are also known for these applications and are often referred to as “fast doors”.
One issue with automatic doors, particularly with fast doors due to their high closing speed, is impacts with obstacles accidentally located within the closing trajectory of the shutter. Besides damaging the obstacle (which can be a human) such impact can damage the leading edge of the shutter and also disengage the bead of the shutter lateral edges from the guiding rail. Systems for automatically reinserting a bead thus disengaged are described e.g., in US20100181033, which disclosure is herein incorporated in its entirety by reference.
Since preventing is better than repairing, many automatic door systems are provided with obstacle and/or impact detection devices. A door provided with an obstacle detection device is described e.g., in US20030071590. A door provided with an impact detection device is described e.g., in US20120073200. In the latter, a safety procedure is described in case of an impact, including stopping the closing of the shutter, opening the shutter to a waiting position and maintaining it at such position for a predetermined waiting time after which the shutter is closed again at normal speed, and just before reaching the position of first impact, at reduced speed. In case no obstacle is detected at the first impact position, closing continues at normal speed. If, on the other hand, the obstacle is still present at the first impact position, the shutter is opened again to the waiting position. If the obstacle is still detected upon several such cycles, the shutter is opened permanently, and must be re-activated manually.
For operator's comfort, as well as for optimizing the closing of the area defined by the frame of the door, many door systems are provided with an automatic closing system, sometimes referred to as “auto-close” doors. In such systems, the door can be opened by a signal sent by an operator, but the operator needs not send a second signal to close the shutter, as it will close automatically after a given time, t. Such doors will be referred to herein as auto-close doors. The danger of impacting an obstacle is even higher with auto-close doors than with manually controlled doors, since the closing may happen in the absence of any operator in the direct neighborhood of the door.
US20030071590 discloses an auto-close door provided with an optical obstacle detecting sensor and a timer for controlling the time the door must remain open before closing. The timer is triggered only after the sensor is interrupted for at least three seconds or more by e.g., the passage of a vehicle in case of a garage door. If, during the closing of the door, an obstruction would occur, the door would return to its open position, and cannot be closed again automatically. An operator must trigger the closing of the door which remain closed for one and one-half minutes before the automatic closing mode can actuated again. This system is interesting because it matches the opening time of the door to the time of passage of a vehicle through the open frame. It is not, however, an intelligent auto-close door because it does not learn and adapt the opening time from its events history.
U.S. Pat. No. 6,924,730 discloses a fire door control system able to automatically close the door upon triggering of an alarm, such as a fire alarm. As the alarm is triggered, a timer is started for waiting a predetermined period of time, before releasing the automatic brake release. In case the door hits an obstacle upon closing, then the door will stop for a given time to allow the obstruction to be removed. Then the system the door is pulsed closed again by the clutch. The door will stop each time an obstruction is encountered. If no obstruction is encountered then the door finishes incrementally closing by the pulsating clutch. Again, this auto-close control system is not intelligent as it does not adapt the time the door remains open to the events history of the door.
EP344404 and U.S. Pat. No. 5,001,557 describe a method for controlling the position of an automatically operated elevator door as a function of the presence, number and movement conditions of one or more persons present on a support surface within a predeterminate space extending on a predetermined side of the automatically operated doo. The method provides a clear and unambiguous indication of the presence, the number and the movement conditions of the one or more persons and permit controlling the operation of the automatically operated door consistent with the indicated presence, number and movement conditions of the one or more persons. This method is advantageous for controlling elevator doors as it adapts the door opening time to each stage when the door is open as a function of the presence and movements of persons at said stage. This method is, however, not suitable for fast doors of the type used in warehouses and industrial halls, and the like because the method is designed for scanning one side only of the door, and scanning both sides would render the control of the door quite complex as the processor would have to interpret the images produced by two cameras.
The present invention provides an intelligent auto-close door capable of learning the optimal time said door must remain open prior to closing automatically. Said learning is based on a number of opening and automatic closing cycle repetitions. This and other advantages of the present invention are presented in continuation.